Silencer attachment for telephones



A. s. CARMAN ET AL SILENCER ATTACHMENT FOR TELEPHONES Filed April 19, 1923 March 10. 1'925 Patented Mar. 10, 1925.

UNITED STATES PATENT OFFICE.

ALBERT S. CARMAN, OF NEW YORK, N. Y., AND JOSEPH A. PERIN, JR., OF EAST ORANGE, NEW JERSEY.

SILENCER ATTACH'MEN'JI FOR TELEPHONES.

Application filed April 19,

To all whom it may concern.

Be it known that we, ALBERT S. OARMAN and JOSEPH A. PERIN, Jr., citizens of the United States, and residents, respectively, of

New York, in the county of New York and State of New York, and of East Orange, in

the county of Essex and State of New Jersey, have invented certain new and use ful Improvements in Silencer Attachments for Telephones, of which the following is a specification.

This invention relates to devices for rendering telephone conversations inaudible except by way of receiving devices forming part of the telephone equipment.

The invention includes an attachment for telephone transmitters which has a relatively small and compact formation but nevertheless having a mouthpiece sufficiently large to receive a considerable area surrounding the lips of the user. By providing a mouthpiece opening sufficiently large to allow full play of the lips and also to include a portion of the nose of the user, a facility of speech that preserves the natural tones of the voice and substantially increases the clearness and audibility of the transmitted sounds over the rendition obtained in the ordinary use of the standard type of transmitter, is obtained. The device is equipped with a cushioned, soundproof mouthpiece edge and has a converglng formation toward the transmitter opening to aid in the transmission of sound waves to the diaphragm.

A feature of the invention resides in the provision of passages through which air can flow into and out of the confined space within the device but which are so formed as to effectually prevent the corresponding passage of sound waves so that in use there can be no formation of pressure or vacuum conditions within the device which would interfere with or prevent speech while, at the same time, the transmission of sound waves to the exterior of the device to render the transmitted speech audible to an unwarranted listener is wholly overcome.

Other features of the invention will be hereinafter referred to.

In the drawings, in which a preferred form of the invention has been selected for illustration,

Figure 1 is a view in side elevation of a 1923. Serial No. 633,073.

device embodying a preferred form of the invention.

Figure 2 is a vertical section of the device shown in Figure l on an enlarged scale.

Figure 3 is a horizontal section of the device shown in Figure 2.

Figures i and 5 are views in transverse and longitudinal section respectively of a modified form of the invention.

Referring to the drawings for a more de tailed description of the invention, a standard type of telephone transmitter is shown at 5 from which projects the usual mouthpiece 6. The present invention includes a generally conical or funnel-shaped member 7 formed of sheet metal or of other material such as vulcanite or similar material, and whose smaller end is provided with a resilient washer 8 adapted to enclose the mouthpiece 6 of the telephone transmitter and to form therewith a sound proof sealing engagement. In order to mount the protective device 7 in position on the telephone mouthpiece 6 the mouthpiece is removed as will be clear and reinserted in its seat through the aperture provided in the small end of the conical member 7. The converging end of the member .7 directly engages the forward face of the transmitter 5 as at 9 at the lower side of the mouthpiece 6 and at the upper side is cut away as at 10 to provide for the reception of the framework 11 of the indicator holder mounted on the usual transmitter.

The forward and larger end of the protective member 7 is provided with a resilient cushioning member 12 which may be formed of soft rubber and which has a skirt or flange extension as at 13 which securely engages the outer surface of the device to provide sealing contact therewith. The open larger end of the device 7 has a vertically elongated formation in the general form of an ellipse and this particular formation particularly adapts the edge cushion member 12 of the device to be pressed into engagement with the face of the user and to include not only the considerable area about the lips of the user but also a portion of the nose including the nostrils. By this arrangement the operation of talking into the transmitter is very greatly facilitated and the production of natural tones is not interfered with. 

